Fuel systems for supplying liquid fuel, by way of non-limiting example only, gasoline or diesel fuel, to an internal combustion engine typically include a fuel tank for storing a volume of fuel, a fuel pump for pumping fuel from the fuel tank to a fuel rail mounted to the internal combustion engine. The fuel rail includes a plurality of fuel injectors such that each fuel injector is arranged to inject fuel to a respective combustion chamber of the internal combustion engine. The fuel rail provides a common volume of fuel from which each of the plurality of fuel injectors receives fuel. The fuel pump is typically designed to provide fuel at a constant flow and pressure that meets or exceeds the requirements of the internal combustion engine at maximum output of the internal combustion engine. However, the internal combustion engine is primary operated below its maximum out capability, and consequently, typically does not require all of the fuel supplied by the fuel pump. Consequently, the fuel system typically includes a fuel pressure regulator which maintains a constant pressure within the fuel rail by recirculating a portion of the fuel pump output back to the fuel tank. The fuel pressure regulator may be located within the fuel tank or remote from the fuel tank.
One type of fuel pressure regulator is shown in United States Patent Application Publication No. US 2011/0186152 A1 to Herrera, hereinafter referred to as Herrera. The fuel pressure regulator of Herrera is commonly referred to as a flow-through fuel pressure regulator because fuel must flow around a valve member in order to pass from a fuel inlet to a fuel outlet. The valve member is biased toward a valve seat by a valve spring such that the force applied by the valve spring holds the valve member against the valve seat when the fuel pressure within the fuel rail is at or below a predetermined fuel pressure, thereby preventing fuel from flowing from the fuel inlet to the fuel outlet. Conversely, when the fuel pressure within the fuel rail is above the predetermined fuel pressure, the fuel pressure overcomes the force of the valve spring, thereby causing the valve member to disengage from the valve seat and allow fuel to flow from the fuel inlet to the fuel outlet. The valve member will remain disengaged from the valve seat until the fuel pressure within the fuel rail is returned to the predetermined fuel pressure, and then the valve spring will again move the valve member into engagement with the valve seat.
While the fuel pressure regulator of Herrera may be effective for regulating the fuel pressure, it is common for fuel pressure regulators such as those disclosed by Herrera to generate vibration and noise. The noise and vibration are the result of axial and lateral movement of the valve member at high frequencies due to the fuel flowing around the valve member. The noise and vibration may be of a magnitude that may be objectionable to a person that is in or about a motor vehicle that includes such a fuel pressure regulator.
U.S. Pat. No. 8,302,622 to De Santiago, hereinafter referred to as De Santiago, teaches a fuel pressure regulator which includes a pressure differential creation structure to create a differential pressure around the valve member which causes unbalanced flow to promote the valve member to move toward a certain location in the open position in an effort to minimize noise and vibration. While the arrangement of De Santiago may reduce noise and vibration compared to the arrangement of Herrera, improvements are continually desired.
What is needed is a fuel pressure regulator which minimizes or eliminates one or more the shortcomings as set forth above.